The present invention relates to a gene relating to cell differentiation (SYG972), amino acid sequence coded therefrom and their application to cancer diagnosis. The present invention also relates to a genomic DNA of SYG972 and to a new promoter.
Cell differentiation is the series of events involved in the development of a specialized cell having specific structure, functional, and biochemical properties. Cell differentiation occurs mainly at the time of fetus formation, but also occurs through out the entire life. Differentiating cells receive specific intracellular signals to participate in cell differentiation according to its program. During this process, expression of many different genes is regulated through a complex path. Genes that regulate cell differentiation are known to encode transcription-regulating factors including homeoproteins and cell cycle proteins. Most of the cell differentiation related genes, however, act on specific cell lines in a specific mode. Nevertheless, a common phenomenon relating to differentiation, that is, differentiation accompanying growth inhibition indicates that there exists a key regulator for cell differentiation. Accordingly, it is necessary to separate the functioning gene and elucidate its function.
One of the most prominent characteristics of cancer cells compared to normal cells is that cancer cells can amplify indefinitely. In order for normal cells to mutate to into cancer cells, the intracellular growth inhibiting genes must be deactivated. One of the representative example is the deactivation of the P53 gene that is found frequently in cancer cells. The product of the P53 genes is intra-nuclear transcription regulating factor for the normal cells, but mutation in this gene results in abnormal growth of the cells and which became cancer cells.
An example of a cancer regression gene closely related to cell differentiation is an erbA gene encoding thyroid hormone receptor. When red blood cell precursor cells are infected with an avian erythroblastosis virus, and the function of the erbA gene is regulated abnormally, this cell differentiates not into red blood cell but into undifferentiated immortalized cancer cells. In other words, generation and progress of cancer cells are complex phenomena that accompany expression of many genes and also accompanies the blocking of cell differentiation. Therefore, it is very important to find factors regulating cell differentiation and growth inhibition in diagnosing and treating cancers.
Promoters, sites regulating the transcription of a gene, are generally located at 5xe2x80x2 position of transcription start site. Gene expression is regulated depending on the transcription factor that binds this domain. In other words, the promoter of the gene determines regulation site for tissue specificity of a specific gene and changes in the expression according to the differentiation. Therefore, cloning a gene promoter and determining the sequence are very important in studying gene expression mechanism and finding gene expression regulating factors.
It is an object of the present invention to provide a cancer diagnosis method using SYG972 gene, its fragment and polypeptide derived therefrom.
It is another object of the present invention to provide a genomic DNA of SYG972.
Another object of the present invention is to provide a sequence for a new promoter.
Another object of the present invention is to provide a method to design and screen drugs by using a promoter of SYG972.